# BYJU'S, monolith to events

https://shubhamnagota.com/work/byjus-event-driven

Order and student domains on Kafka, plus $110K a month cut from AWS.

## Problem

The order and student domains lived in one monolith.

## Constraints

- The student service had to be low-latency and highly available for 2M+ active users.
- A team of 4 engineers, which I led and mentored.

## What I built

I split the monolith into order and student microservices that talk through Kafka, running on AWS ECS.

Diagram (From monolith to event-driven services): Monolith, then Kafka events, then Order service, then Student service.

## Outcome

- 3x concurrent orders.
- 40% better performance and 60% less processing time.
- $110K+ a month saved on AWS.
- 70% fewer production incidents, with APM monitoring and alerting on Datadog, Prometheus and Kibana.
- 50% fewer production errors through TDD.